FIGS. 4 and 6 of U.S. Pat. No. 4,809,972 illustrate an example of a leg extension/curl exercise station having a tilt-up seat with a fixed semi-reclined back rest. A front swing member depends from a pivot connection with the support for the seat and has a padded pair of laterally extending leg engagement arms adjacent its lower end. A loaded cable resists forward swinging movement of the swing member.
When performing the leg extension exercise the exerciser is seated and has his(her) legs positioned behind the leg engagement arms. Both legs are then swung forwardly at the knees while in engagement with the back of the leg engagement arms so that the swing member is swung upwardly under the load exerted by the loaded cable. During this swinging motion the cable is guided around an arched cable guide member at the back of the swing member.
When performing the leg curl exercise the exerciser faces rearwardly and grasps the handles on the sides of the seat with the seat locked in a tilted upright position. The exerciser than swings his legs rearwardly at the knee, one at a time., from floor contact so that the back of the swung leg engages the back of the respective leg engagement arm. Further leg swing causes the swing member to swing forwardly of the seat in opposition to the loaded cable.
The described mechanism does not have provision for various leg lengths and hence the leg engagement arms slide part way along the legs of some exercisers while they are performing the leg extension and/or leg curl exercisers. This problem can be partly solved by slide mounting the leg engagement arms on the swing member for pin connection to any of a series of holes in the swing member. However, if the exercise machine is used by several people it is annoying to make multiple adjustments of the leg engagement arms.